[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: contour fill

On 26 Aug 2000, Craig Markwardt wrote:

> davidf@dfanning.com (David Fanning) writes:
> > Leaving aside the observation that getting *something*
> > to work is not exactly the same as getting the *right*
> > thing to work, I'm still concerned that the poor fellow
> > is not working on the right thing. :-(
> > 
> > Unless your goal is some kind of pseudo-science, working
> > with the representation of the data rather than the data
> > itself is rarely a good idea.
> He was asking *how?*.  You are asking *why?*.  Both are fair
> questions.
> You wondered why a basic threshold wouldn't work.  I think his reply
> was that he wanted to select a *particular* contour.  When there are
> several peaks in the data then a simple threshold will not work.  As I
> pointed out the hardest part in the algorithm I gave is selecting the
> right contour.  [And I gave a posible heuristic to decide.]
> Craig
> -- 
> --------------------------------------------------------------------------
> Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
> Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
> --------------------------------------------------------------------------

That's right. I need a particular contour which is well defined and there
is a well rigorous physical meaning to what I am trying to do. It is
of course the representation of the data which I am manipulating and the I
fully understand that interpretation of this representation is important
if proper physical sense is to be made. 

I haven't tried the suggestions which have been posted but when I have
I'll let you know how they work compared to a C program I have written to
do the job. 

Cheers, Stephen

Dr Stephen O'Sullivan                 | Telephone: +44-113-2335187 
Department of Applied Mathematics     | Facsimile: +44-113-2429925
University of Leeds		      | Email    : so@amsta.leeds.ac.uk   
Leeds LS2 9JT UK                      | WWW: www.amsta.leeds.ac.uk/applied